Chilling effects

Charles DuhiggTimes Staff Writer

Lost in the Sierra, snowboarder Eric LeMarque wandered miles from Mammoth Mountain for one week in sub-zero conditions last winter. Sweat froze his skin, he lost sensation in his legs, and one foot swelled so much that he could not fit it in his shoe, forcing him to hike barefoot for a day. He was disoriented when rescuers found him, and two days later surgeons amputated his feet and part of his legs due to frostbite.

But ongoing research suggests LeMarque's ordeal may not be over. Long-term frostbite damage persists even after freezing injuries heal. Chronic effects include arthritis, muscle atrophy, fused joints and circulatory problems — conditions once thought unrelated to freezing, says retired physician Dr. William Mills, a national expert who has studied frostbite for decades in Alaska.

"Frostbite might be more serious than we thought," Mills says.

As winter snow play season begins, at least 6 million enthusiasts will take to frozen woods, iced lakes and frosted peaks across the nation to ride snowmobiles, ski, climb ice, snowboard and hike.

The American Red Cross predicts thousands of people can expect to suffer frostbite this winter. Cold-weather enthusiasts should wear warm layers, keep dry, consume liquids and carbohydrates and seek shelter and warmth at the first sign of numbness.

Frostbite doesn't strike everyone the same, but it generally starts once skin temperature plummets to 26 degrees Fahrenheit and blood chills to 45 or 50 degrees. Capillaries that deliver oxygen to muscles and skin freeze, fluid between cells turns to ice and cell membranes rupture as blood clots.

Damage stops once cells freeze — cold can preserve flesh much like meat in a freezer— until tissue warms again. But when fluid on the cell surface thaws and then instantly refreezes, more damage occurs. As the freeze-thaw cycle continues, cell damage mounts until flesh dies, turns black, shrivels and falls off or becomes infected. Completely frostbitten limbs must be amputated.

In the 19th century, doctors began treating frostbite by gradually warming frozen limbs, a lesson learned after the French army bogged down in snow during Napoleon's 1812 invasion of Russia. Retreating soldiers built fires to thaw, but often burned themselves irreparably. Napoleon's chief general, Baron Dominique-Jean Larrey, banned rapid rewarming and opted for massaging frostbitten limbs with snow, a technique used until World War II.

In the 1950s, Mills advanced research previously done at Stanford University exploring rapid rewarming of frostbitten limbs. He found that frozen limbs immersed in warm water healed best because cellular liquids would refreeze less frequently, thus minimizing damage.

Mills has since explored long-term consequences of frostbite. He studied 70 Korean War veterans who suffered frostbite during the retreat at the Chosin Reservoir. Today many of the men suffer from deformities and other injuries, including arthritis and degenerative joint disease.

"If we know these conditions are a result of frostbite, we can change treatment techniques," says Mills. "We might even prevent long-term injuries by changing how we treat frostbite when it occurs."

Mills is one of the few scientists who still study frostbite. As the military turned its attention to desert and jungle warfare, research on frostbite waned.

"Mills has seen more frostbite than anyone," said Dr. Bruce Paton, a cold injury specialist based in Colorado. "He's almost single-handedly pushed this medical field forward."

The long-term consequences of frostbite, however, continue to plague those who suffer them. Jeff King, a three-time Iditarod Sled Dog Race champion, lost the tips of two fingers after his hand froze during a race in 1987.